This invention relates to a cabinet system. It relates especially to cabinets adapted to house computer equipment, telecommunications apparatus and the like and to a method of assembling those cabinets to form a plural-cabinet system.
Standard computer cabinets designed to support relatively heavy loads usually comprise individual vertical and horizontal frame members connected together to define a rectilinear frame structure or rack. Panels may be secured to the frame members to enclose the cabinet contents. To enable the cabinet to withstand the rigors of shipping and handling, the frame members usually consist of steel tubes or channels because these are inherently strong shapes. The contents of the cabinet, e.g., processors, controllers, fan units, power supplies, etc. are usually made as slide-in units or modules which must fit within the interior space defined by the frame members. Since the frame members must have a relatively large cross section, i.e., two inches or more, to give the cabinet enough strength to withstand shipping, handling and joining together, this means that the distance between the sides of the slide-in modules or units within the cabinet and the outer surface of the cabinet side wall must be in excess of two inches.
In typical computer installations, it is sometimes desirable to be able to increase the processing power of a computer by adding to the modules in one cabinet additional slide-in modules in a second similar cabinet. This is usually accomplished by positioning the second cabinet next to the first one and mechanically joining the two together taking pains to ensure that both cabinets are level and in vertical and horizontal alignment. This process usually requires at least two field technicians, particularly if the surface supporting the cabinets is not level to begin with. Then, the technicians make the necessary electrical connections between the modules in the two cabinets. Since the slide-in modules in the two cabinets are spaced apart by their respective frame members (and any side panels), the electrical connections or signal paths between the modules in the two cabinets must be at least four inches long.
While this may not have been a problem when computer processing speeds were relatively low, it has become so with today""s computer systems which operate at clock speeds of 9.6 ms and lower. In other words, it is now essential to minimize the lengths of the signals paths between various modules or subassemblies of a computer system, digital switching system or the like without compromising the strength and durability of the cabinets which house those modules or subassemblies.
Accordingly, it is an object of the present invention to provide a cabinet structure for a computer, telecommunication apparatus or the like which can withstand shipping, installation and leveling loads.
Another object of the invention is to provide such a cabinet which minimizes the spacing of the cabinet contents from the exterior sides of the cabinet.
A further object of the invention is to provide a cabinet of this type which has a relatively small footprint.
Yet another object of the invention is to provide a cabinet structure which facilitates the coupling together in the field of two similar cabinets and their contents.
A further object of the invention is to provide a cabinet system composed of a plurality of cabinets coupled together side by side so as to minimize the lengths of the signals paths between the equipment in the two cabinets.
A further object of the invention is to provide a plural-cabinet system of this type which can repose in stable alignment even on an uneven support surface.
Yet another object is to provide a method of joining together two cabinets of the above type.
Other objects will, in part, be obvious and will, in part, appear hereinafter. The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the following detailed description, and the scope of the invention will be indicated in the claims.
In accordance with the present invention, our cabinet for computer equipment and the like is devoid of frame members at the sides of the cabinet. Rather, the side frame members are substituted for by rigid metal side plates that are connected together at various elevations on the cabinet by horizontal box frames which are welded to the side plates to form a very stiff, rigid box-like structure which is resistant to racking, bending and buckling even under a heavy load. Each stiffened cabinet side wall is quite thin so that the cabinet contents may be spaced quite close to the exterior sides of the cabinet. This allows two such cabinets to be positioned side by side so that the cabinet contents can be juxtaposed within half an inch instead of the four inches required by conventional steel frame cabinets or racks, while providing the same level of strength. Thus, our cabinet with welded-together steel side plates minimizes the lengths of the signal paths between the contents of the two cabinets. This enables a minimum capacity computer system to be shipped in one cabinet and expanded later if necessary by adding additional processing capacity in a second cabinet coupled to the first cabinet. Indeed, our cabinet design enables a single technician to join and level the cabinets in the field to form a single cabinet system even when the cabinets are supported on an uneven support surface.
For this, one side wall or plate of the first cabinet is provided with coupling means including a plurality of alignment or locating holes. Two such holes, which are round, are spaced apart horizontally and located adjacent the cabinet""s lower stiffening box frame. A third alignment hole is situated adjacent the upper box frame more or less directly above one of the aforesaid lower holes. Preferably, this upper hole is vertically elongated, e.g., oval, for reasons that will become apparent. The coupling means also include a pair of threaded bolt holes located in the side wall at the lower box frame adjacent that wall""s side edges. A third threaded bolt hole is present in the side wall at the upper box frame more or less midway between the side edges of that wall.
To facilitate siting the first cabinet at a particular destination, the cabinet is provided with wheels and conventional screw-type levelers so that once the cabinet is placed at the desired location in a utility or computer room, it can be leveled to compensate for an uneven floor surface.
At some point, it may become necessary or desirable to expand the computer in the first cabinet by adding additional processing capacity. In that event, a second cabinet, somewhat similar to the first one and containing additional processors, may be rolled into place beside the first cabinet and the two cabinets coupled together using coupling means on the second cabinet which cooperate with the aforesaid coupling means on the first cabinet. More particularly, the side wall of the second cabinet that faces the first cabinet is provided with a plurality of laterally projecting locating or alignment pins which are adapted to mate with the corresponding alignment holes in the side wall of the first cabinet. Thus, the side wall of the second cabinet has two horizontally spaced-apart pins adjacent the lower horizontal box frame of that cabinet. A third pin is located in the side wall opposite the upper box frame just above one of the lower pins. In other words, when the two cabinets are placed side by side, the pins extending from the side wall of the second cabinet are located substantially opposite the alignment holes in the opposing side wall of the first cabinet. As we shall see, the alignment pins are tapered and have axial symmetry. Therefore, when the two cabinets are brought together in a manner to be described, the pins on the second cabinet side wall extend into and become centered in the locating holes on the first cabinet side wall so that the two walls become aligned both vertically and horizontally. Also, three bolt holes are provided in the same side wall of the second cabinet at positions corresponding to those of the threaded bolt holes in the first cabinet.
In order to couple the second cabinet to the already sited and leveled first cabinet, the former cabinet, with its levelers raised, is rolled next to the first cabinet so that the alignment pins in the side wall of the second cabinet are positioned more or less directly opposite the corresponding alignment holes in the side wall of the first cabinet. Next, a coupling bolt is inserted through one of the lower bolt holes in the second cabinet and threaded into the corresponding hole in the first cabinet. Also, a coupling bolt is inserted through the upper bolt hole in the second cabinet and turned down into the corresponding threaded bolt hole in the first cabinet.
The aforesaid lower bolt is tightened first so that the adjacent one of the lower locating pins on the second cabinet is drawn into the corresponding locating hole in the first cabinet. Preferably, this hole is a relatively tight fitting hole so that the base of the second cabinet becomes aligned with that of the first cabinet in both the horizontal (X) and vertical (Y) directions. Then, the upper bolt is tightened so that the aforesaid pin-in-hole connections draw the corresponding cabinet side wall edges together so that they are in XY alignment. The fact that the upper locating hole in the first cabinet is vertically elongated allows the corresponding locating pin on the second cabinet to swing through an arc and still be received in that upper hole to achieve alignment of the cabinets in the event that the underlying support surface is not level such that the side walls of the two cabinets are initially not parallel. Finally, a third coupling bolt is inserted through the other lower bolt hole in the second cabinet and turned down into the corresponding threaded bolt hole in the first cabinet to complete the assembly of the two cabinets so that they abut one another and are in alignment in all three (X,Y,Z) directions.
We should emphasize at this point that the formation of the cabinets with rigid welded-together and stiffened side plates enables the stationary first cabinet to support the entire weight of the second cabinet as the latter cabinet is being joined to the first cabinet. That is, as the pin-and-hole connections are made between the two cabinets and the second cabinet is leveled and brought into alignment with the first as the coupling bolts are tightened, part or all of the second cabinet may actually be lifted off the support surface, particularly if the surface under the two cabinets is uneven. Once the joining process is completed, the levelers on the second cabinet may be lowered to the support surface so that the weight of that cabinet is borne directly by that surface.
Once joined, the slide-in modules in the two cabinets are separated by less than one-half inch. Therefore, the lengths of the signal paths connecting those modules can be kept to a minimum. Also, this construction minimizes the footprint of the joined-together cabinets thus minimizing expensive computer or utility room overhead.